People have searched the lake in northern Scotland where "Nessie" is supposed to live. No one has found a large creature swimming in its waters. We have the same problem with other mysterious creatures. Scientists do find new species of plants and animals every now and then, or they find something they thought had died out long ago. But remember that an animal doesn't live by itself. There has to be others of its own kind, otherwise the population dies out. So, if there are enough creatures to survive, and they're big, then we should have a good chance of finding them. As for dinosaurs, perhaps some of the smaller ones could live today. No one really knows why they died out in the first place. Dinosaurs were one of the many creatures that were on Noah's ark, but which did not survive for very long afterwards. Perhaps the world was different after the Flood, and they couldn't learn to live in their new environment. By the way, some scientists who believe in evolution suggest that the dinosaurs never died out: they just became birds. When you look out your window and see a sparrow, they say, you're looking at T. rex's cousin! Although some dinosaurs and a few extinct birds had a few body parts that looked similar, dinosaurs did not evolve into birds. God created birds on Day 5 (Genesis 1:20-23), while He created other animals, such as dinosaurs, on Day 6 (Genesis 1:24-31).
As for dinosaurs, perhaps some of the smaller ones could live today. No one really knows why they died out in the first place. Dinosaurs were one of the many creatures that were on Noah's ark, but which did not survive for very long afterwards. Perhaps the world was different after the Flood, and they couldn't learn to live in their new environment.
By the way, some scientists who believe in evolution suggest that the dinosaurs never died out: they just became birds. When you look out your window and see a sparrow, they say, you're looking at T. rex's cousin! Although some dinosaurs and a few extinct birds had a few body parts that looked similar, dinosaurs did not evolve into birds. God created birds on Day 5 (Genesis 1:20-23), while He created other animals, such as dinosaurs, on Day 6 (Genesis 1:24-31).